Antineoplastic resistance

Antineoplastic resistance, often used interchangeably with chemotherapy resistance, is the resistance of neoplastic (cancerous) cells, or the ability of cancer cells to survive and grow despite anti-cancer therapies.^[1] In some cases, cancers can evolve resistance to multiple drugs, called multiple drug resistance.

There are two general causes of antineoplastic therapy failure: Inherent genetic characteristics, giving cancer cells their resistance and acquired resistance after drug exposure, which is rooted in the concept of cancer cell heterogeneity.^[1] Characteristics of resistant cells include altered membrane transport, enhanced DNA repair, apoptotic pathway defects, alteration of target molecules, protein and pathway mechanisms, such as enzymatic deactivation.^[1] Since cancer is a genetic disease, two genomic events underlie acquired drug resistance: Genome alterations (e.g. gene amplification and deletion) and epigenetic modifications. Cancer cells are constantly using a variety of tools, involving genes, proteins, and altered pathways, to ensure their survival against antineoplastic drugs.